I can't speak for German law, but in the UK the
Alternative Fuel Infrastructure Regulations (which are the UK law implementing the relevant
EU directive) most of the provisions only apply to chargepoints "accessible to the public", and the definition of that (see clause 2.(2)) does not cover Superchargers - there's an exemption for "exclusive use in respect of a vehicle produced by a specific manufacturer". There are also exemptions to cover workplace charging, domestic charging, and taxis.
If the Superchargers DID fall under the regulations, then not only would they have to support CCS, they would also have to support "ad-hoc access" (see clause 5):
“ad-hoc access” means the ability for any person to recharge an electric vehicle without entering into a pre-existing contract with an electricity supplier to, or infrastructure operator of, that recharging point.
So it appears to me that the current move to CCS on the Model3 is all about the cars, and doesn't particularly help them with their obligations for infrastructure, though it's possible that in some cases it will be helpful - each country transposes the directive differently. The directive itself defines "accessible to the public" in the opposite sense - points are considered accessible to the public when they meet all the requirements for non-discriminatory access, and member governments are just required to arrange that there are enough of them, not to require that all points are "accessible to the public".